Aerosols composed of biological particles include a small fraction of the aerosols present in our atmosphere. Nonetheless, there is an increasing interest in analyzing biological aerosols, which can incorporate bacteria, fungi, pollens and other biological particles. Certain diseases, for example, tuberculosis, influenza and pneumonia, are transmitted via airborne particles or droplets. Diseases that affect livestock and other farm animals, (e.g. anthrax and brucellosis) and diseases that affect crops, likewise are transmitted through the air. In addition, airborne pollens can cause allergic reactions in humans.
The recent rise in terrorist activities and potential military confrontations with rogue nations has increased concerns over the viability of weapons of mass destruction such as biological weapons. Biological weapons can include biological agents such as bacillus anthracis (anthrax), cholera toxin, influenza, and smallpox virus, among others. Military personnel in the field can be exposed to biological agents in a variety of ways, such as by exploding a device in the vicinity of the target, by releasing one or more agents at a location upwind from the target area, etc. In addition, biological agents may be delivered to occupants within a civilian or military building by releasing the agents within the building or external to the building but close to an air intake of the building. The building's heating, ventilating, and air conditioning (HVAC) system may then rapidly deliver the released biological agent into and/or throughout the building.
As such, the study of airborne bioparticles is now recognized as a key concern, and has an increased role in such diverse areas as epidemiology, DNA genomic analysis and other medical fields, agriculture, building management, food- and water-quality monitoring, and defense, to name just a few. A number of systems have been developed to detect bioparticles in a sample. However, most of these systems are large and expensive, and are not amenable to large scale production and use.